Rivet analyses referenceMARKII_1979_I143939Measurement of $R$ and $D\bar{D}$ cross section between 3.67 and 3.872 GeVExperiment: MARKII (SPEAR) Inspire ID: 143939 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of $R$ and the $D\bar{D}$ cross section in $e^+e^-$ collisions between 3.67 and 3.872 GeV The individual hadronic and muonic cross sections are also outputted to the yoda file so that ratio $R$ can be recalcuated if runs are combined. Source code: MARKII_1979_I143939.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/UnstableParticles.hh"
5
6namespace Rivet {
7
8
9 /// @brief Add a short analysis description here
10 class MARKII_1979_I143939 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(MARKII_1979_I143939);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 declare(FinalState(), "FS");
23 declare(UnstableParticles(), "UFS");
24 book(_c_hadrons, "/TMP/sigma_hadrons");
25 book(_c_muons, "/TMP/sigma_muons");
26 book(_c_DD, "/TMP/sigma_DD");
27 }
28
29 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
30 for (const Particle &child : p.children()) {
31 if(child.children().empty()) {
32 nRes[child.pid()]-=1;
33 --ncount;
34 }
35 else
36 findChildren(child,nRes,ncount);
37 }
38 }
39
40 /// Perform the per-event analysis
41 void analyze(const Event& event) {
42 const FinalState& fs = apply<FinalState>(event, "FS");
43 // total hadronic and muonic cross sections
44 map<long,int> nCount;
45 int ntotal(0);
46 for (const Particle& p : fs.particles()) {
47 nCount[p.pid()] += 1;
48 ++ntotal;
49 }
50 // mu+mu- + photons
51 if(nCount[-13]==1 and nCount[13]==1 &&
52 ntotal==2+nCount[22])
53 _c_muons->fill();
54 // everything else
55 else
56 _c_hadrons->fill();
57 // identified final state with D mesons
58 const FinalState& ufs = apply<UnstableParticles>(event, "UFS");
59 for(unsigned int ix=0;ix<ufs.particles().size();++ix) {
60 bool matched = false;
61 const Particle& p1 = ufs.particles()[ix];
62 int id1 = abs(p1.pid());
63 if(id1 != 411 && id1 != 421) continue;
64 // check fs
65 bool fs = true;
66 for (const Particle & child : p1.children()) {
67 if(child.pid()==p1.pid()) {
68 fs = false;
69 break;
70 }
71 }
72 if(!fs) continue;
73 // find the children
74 map<long,int> nRes = nCount;
75 int ncount = ntotal;
76 findChildren(p1,nRes,ncount);
77 // loop over the other fs particles
78 for(unsigned int iy=ix+1;iy<ufs.particles().size();++iy) {
79 const Particle& p2 = ufs.particles()[iy];
80 fs = true;
81 for (const Particle & child : p2.children()) {
82 if(child.pid()==p2.pid()) {
83 fs = false;
84 break;
85 }
86 }
87 if(!fs) continue;
88 if(p2.pid()/abs(p2.pid())==p1.pid()/abs(p1.pid())) continue;
89 int id2 = abs(p2.pid());
90 if(id2 != 411 && id2 != 421) continue;
91 if(!p2.parents().empty() && p2.parents()[0].pid()==p1.pid())
92 continue;
93 map<long,int> nRes2 = nRes;
94 int ncount2 = ncount;
95 findChildren(p2,nRes2,ncount2);
96 if(ncount2!=0) continue;
97 matched=true;
98 for(auto const & val : nRes2) {
99 if(val.second!=0) {
100 matched = false;
101 break;
102 }
103 }
104 if(matched) {
105 _c_DD ->fill();
106 break;
107 }
108 }
109 if(matched) break;
110 }
111 }
112
113
114 /// Normalise histograms etc., after the run
115 void finalize() {
116 Estimate0D R = *_c_hadrons/ *_c_muons;
117 double fact = crossSection()/ sumOfWeights() /nanobarn;
118 double sig_h = _c_hadrons->val()*fact;
119 double err_h = _c_hadrons->err()*fact;
120 double sig_m = _c_muons ->val()*fact;
121 double err_m = _c_muons ->err()*fact;
122 Estimate1DPtr hadrons;
123 book(hadrons, "sigma_hadrons");
124 Estimate1DPtr muons;
125 book(muons, "sigma_muons" );
126 Estimate1DPtr mult;
127 book(mult, 2,1,1);
128 for (auto& b : mult->bins()) {
129 if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
130 b.set(R.val(), R.errPos());
131 hadrons->bin(b.index()).set(sig_h, err_h);
132 muons ->bin(b.index()).set(sig_m, err_m);
133 }
134 }
135 double sigma = _c_DD->val()*fact;
136 double error = _c_DD->err()*fact;
137 book(mult, 3,1,1);
138 for (auto& b : mult->bins()) {
139 if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
140 b.set(sigma, error);
141 }
142 }
143 }
144
145 /// @}
146
147
148 /// @name Histograms
149 /// @{
150 CounterPtr _c_hadrons, _c_muons, _c_DD;
151 /// @}
152
153
154 };
155
156
157 RIVET_DECLARE_PLUGIN(MARKII_1979_I143939);
158
159
160}
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